For a general vehicle, such as a car, during turning or backing thereof, a driver must keep watching right and left side rear-view mirrors and an interior rear-view mirror to obtain situations around right, left and back sides of the car to ensure driving safety. However, conventional rear-view mirrors whether they are manually or electrically adjustable are fixed at predetermined positions of the car. Even the electric rear-view mirrors can only allow the driver to adjust view angles thereof through an electric means. When the driver is turning or backing the car, the view angle of the rear-view mirror may change or decrease along with the movement of the car, thus causing visually blind spots that make the driver not able to realize all situations around the car and adversely affect the driving safety.
In order to overcome the above drawback that the conventional electric rear-view mirror cannot change its view angle along with the movement of the car, Taiwanese Patent No. 467051 has disclosed an automatically controlling device for view angles of rear-view mirrors of a car. This device comprises two sets of direct current (DC) motors for respectively driving right and left side rear-view mirrors, wherein each of the DC motors is connected to a control circuit, and the two control circuits are operationally coupled to switches of indicators associated with a steering wheel respectively. When a driver operates or switches on one of the indicator switches for turning the car, the corresponding control circuit would be actuated to drive the DC motor to deflect the corresponding side rear-view mirror in accordance with the turning angle of the car, such that a view angle of the side rear-view mirror can be increased and blind spots can be reduced during turning of the car. When the turning is complete and the car goes straight, the indicator switch automatically reverts to an off state, and the control circuit drives the DC motor to restore the side rear-view mirror to an original view angle. This thus improves the driving safety.
Every time when the driver switches the indicator on, the side rear-view mirror would be correspondingly driven to deflect. However, the indicator may be operated frequently during driving of a whole day, thereby resulting in frequent movements of the side rear-view mirror. Such frequent movements would cause the side rear-view mirror to deviate from an originally set view angle or not able to return to the originally set view angle. If the deviation in view angle is not significant, it may not cause a great effect on driving. On the contrary, if this deviation of the view angle is sufficient to cause visually blind spots during driving, since the driver usually relies on images captured by the side rear-view mirror, the presence of blind spots would lead to driving unsafety.
Generally, a car is usually used by a regular driver. However, sometimes a person other than the regular driver may drive the car and needs to adjust rear-view mirrors to appropriate view angles since different persons have different body figures and different angles of watching the rear-view mirrors. When the car is returned to the regular driver, the rear-view mirrors should be re-adjusted by the regular driver to the view angles suitable for the regular driver, thus causing inconvenience and trouble to the regular driver.
In addition, if the regular driver does not notice that the rear-view mirrors have been adjusted by another person and replies on images captured by such rear-view mirrors that may have view angles not suitable for the regular driver, this would easily lead to visually blind spots for the regular driver and adversely affect the driving safety.